Ulysses/Words/Parallax

Parallax refers to the effect of a position or direction of an object changing because it is being viewed from a different position. One example might be, looking up at the night sky, and seeing clouds moving at one speed, and stars remaining fixed. The root is the French word "parallaxe" from the Greek "parallaxis" (a change) - root "allos" (other).

'"Parallel" is a related word, meaning occurring or existing at the same time or in a similar way; corresponding.